A bicycle speed change assembly for sports type bicycles such as racing bikes has been commonly mounted on a bicycle frame member such as a down tube or a top tube. This location unavoidably requires that a cyclist must unhand, i.e., release the handlebar to achieve a speed change operation. It is only natural, therefore, that during a speed change operation a cyclist has no immediate access to a braking apparatus. In addition, the single-handed cycling unavoidably leads to an unstable handlebar operation.
On the other hand speed change operation is required in general when there is a change in road condition, for example, from a flat road to a slope, or vice versa. In such occasions, however, brake operation is also often called for since such change in road condition often leads to less stable riding.
To alleviate this problem a conventional speed change operation assembly has been mounted, for example, on a handle grip portion or in proximity with a brake lever in an attempt that the handlebar or the brake may be accessed as quickly as possible from the speed change operation lever. Indeed this has been the only way to improve riding safety during a speed changing operation.
No matter how close the speed change operation lever is located to the brake lever or handlebar grip portion, the speed change operation does require the cyclist's hand to leave the handlebar or the brake lever, and as a result single-handed cycling is unavoidable. Disturbed access to a brake is likewise unavoidable.
In an attempt to solve this problem a proposal has been made for example as in the Japanese Patent Application Laid-open No. Hei-2-147487 which discloses a speed change operation assembly wherein a speed change operation lever extends out of a brake bracket.
However, the speed change operation assembly disclosed thereinabove has a problem of limited application; it is only applicable to what is known as a drop-type handlebar, and therefore bicycles mounted with other types of handlebars are out of the scope of application.
Furthermore, that particular speed change operation assembly disclosed thereinabove requires that for speed change operation either a thumb or a forefinger must be released from a handlebar grip. Therefore, it does not provide a cyclist with immediate access to a braking apparatus, or it does not solve, either, the problem of disturbed handling stability.